If you really want Germans, put a very wide, smooth layer of vaseline at the top, and put the crotch of tights, knotted with legs cut off, over the top of the container then put the lid on. Apparently keeps the dreaded hisser nymphs in.
I don't have experience with this species, but vasaline generally works. If you have doubts, tigh the legs of a pair of ladies' tights together and cut the legs off, keeping the knot. Then stretch the crotch over the enclosure top and put the lid on. Use vasaline in a 2-inch thick line at the top, spread as smoothly as you can(old credit/iTunes cards do it well) so the tights are like a second barrier.
i used folded loo roll, wooden rodent cage decor that had been wrecked, and a variety of other small cardboard items i had. not natural but easily sourced and great for hiding lol.
Unfortunately i had to relocate my roaches before i could try it, but tie the legs of ladies tights in a knot then cut the legs off. Stretch the crotch part over then put the lid on.